By Peter Jones

August 21, 2025

Security guarantees have emerged as a key issue in the current diplomacy over Ukraine.

Ukraine has had such guarantees before, and they amounted to very little. In the wake of the Cold War, Ukraine had nuclear weapons on its soil belonging to the former USSR. In fact, Ukraine had the third-largest nuclear stockpile in the world at the time, amounting to some 1,900 strategic warheads, 176 intercontinental ballistic missiles (ICBMs), and 44 strategic bombers.  They did not have the codes necessary to launch them, which remained with Russia, but could probably have cracked them, in time.

After some intense diplomacy, Ukraine agreed to give these weapons up, in return for a guarantee that it would not be attacked by any nuclear armed power. This was issued in January, 1994 in the form of the Budapest Memorandum, signed by Ukraine, Russia, the United States and the United Kingdom. It was meant to assure Ukraine that giving up the nuclear weapons they had inherited would not expose them to attack by a country that still had them, notably Russia.

In 2014, Russia attacked Ukraine, taking over Crimea and parts of the Donbas region. The 1994 security guarantee had amounted to nothing. In response to the 2014 attack, an agreement was reached in Minsk in 2015 in which the vague phrase “security assurances” was used – but was interpreted differently by different actors.

None of it made any difference when Putin attacked Ukraine again in 2022. This time, however, we are told that the security guarantee will be different.

The gold standard of security guarantees is NATO’s Article 5, which says that an attack on one is an attack on all and shall be resisted by all. Trump and Putin have ruled out Ukraine actually joining NATO, but there is talk of an “Article 5-type” guarantee for Ukraine in place of NATO membership.

So, what does Article 5 of the North Atlantic Treaty say:

“The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.”

What Article 5 actually says is that an attack against one is indeed an attack against all, but that each member of the Alliance shall take such action as it deems necessary, including the use of armed force…”  In other words, a military attack on a member of NATO does not automatically require the others to use force to repel it. It is not really an ironclad assurance of military assistance.

Western countries may be prepared to issue yet another security guarantee to Ukraine but have ruled out stationing troops in Ukraine to back it up.

What made Article 5 serious was the fact that it was backed up by hundreds of thousands of allied troops stationed in Germany. Whatever Article 5 may have said on paper, the Soviets knew, as a practical reality, that if they ever attacked West Germany, they would not face a group of countries who would “individually and in concert with the other parties, (take) such action as (they) deem necessary….”  Rather, the Soviets knew that they would immediately be at war not just with West Germany, but with the US, Britain, Canada and several other countries.

This matters greatly to Ukraine today. Western countries may be prepared to issue yet another security guarantee to Ukraine but have ruled out stationing troops in Ukraine to back it up.

For his part, Putin, understanding only too well the lessons of the Cold War, has flatly said he will not sign an agreement that allows for such troops to be stationed there. Indeed, his foreign minister, Sergey Lavrov, has suggested that Moscow should have a veto over whether the guarantees could ever be invoked – an obvious non-starter.

Trump, for his part, says the US will not put boots on the ground even in response to another invasion of Ukraine, but might support a European military response. The Europeans are making noises to the effect that they might be willing to undertake a military response in support of Ukraine, but only if the US will promise to back them up.

President Zelensky can be forgiven for being less than impressed. He knows from bitter experience that security guarantees on paper amount to little unless Putin knows deep in his black heart that any invasion of Ukraine will be met by a united Western military response.  Otherwise, Ukraine must rely on its own armed forces – which makes Putin’s requirements that Ukraine effectively disarm itself as part of a peace agreement, and that the West stop supplying it with weapons, a transparent attempt to leave Ukraine defenceless.

President Trump’s apparent desire to end the war in Ukraine is leading him to accept Putin’s formula and to put pressure on Ukraine to accept what effectively amounts to a ceasefire for a few years while Russia re-arms before attacking Ukraine again. The security guarantees that will accompany any agreement will be about as robust as the ones Ukraine received in 1994 and 2015.

The alternative is for the allies to give Ukraine the military and financial support it needs to fight on and also to punish Russia as forcefully as we can (economically at least) to get them to stop.  The Europeans (and Canada) say they are prepared to do that, but Trump is no longer interested.  He claims to have had enough of “giving” Ukraine support, though he is willing to sell weapons to Europe so that they can give them to Ukraine. And he really wants to get along with Putin much more than he cares about upholding the sanctity of that irritating bit of international law which says that borders shall not be changed by force.

In 1947, as smaller European countries feared growing intimidation by the USSR and its proxies, President Truman went before a joint session of the Congress to declare that, “I believe it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures….”  The Trump Doctrine might add, “provided we can make a buck and not upset my autocratic mentor too much.”

Peter Jones is a Professor in the Graduate School of Public and International Affairs at the University of Ottawa. He is also Executive Director of The Ottawa Dialogue, a University-based organization that runs Track 1.5 and Track Two diplomatic dialogues around the world.